What Font Does Slack Use?

Slack displays messages using your operating system's native sans-serif font. That means San Francisco on macOS and iOS, Segoe UI on Windows, and Roboto on Android. For its brand materials, loading screens, and select UI labels, Slack uses a proprietary sans-serif typeface introduced during its 2019 rebrand.

Slack's current font stack

Slack takes a system-font approach to message rendering. Rather than loading a custom web font for every line of chat, it defers to the default sans-serif installed on your device.

Here's what that looks like in practice:

• macOS and iOS: San Francisco
• Windows: Segoe UI
• Android: Roboto
• Linux: varies by distribution (often Noto Sans or DejaVu Sans)

This approach keeps messages readable and fast-loading. System fonts are already cached on your device, so there's zero download overhead when you open Slack.

For code blocks and inline code (text wrapped in backticks), Slack renders in a monospace font. On macOS that's typically Menlo, on Windows it's Consolas, and on Linux it's usually the system monospace default.

The brand typeface

Slack's marketing website, splash screens, and certain UI headings use a proprietary sans-serif typeface. Unlike Instagram Sans or Twitter's Chirp, Slack has not widely publicized the name of this typeface. It appears in blog posts, the desktop loading screen, and promotional materials.

The typeface is geometric, clean, and slightly rounded at the terminals. It pairs naturally with the bright, blocky color palette Slack adopted in 2019.

A brief history of Slack's typography

Pre-2019: Slack used Lato, an open-source sans-serif designed by Lukasz Dziedzic. Lato appeared throughout the interface and was recognizable for its semi-rounded letterforms and friendly tone.

2019 rebrand: Slack overhauled its visual identity. The old tilted plaid hashtag logo was replaced with the current solid-color octothorpe mark. Alongside this, Slack retired Lato in favor of a custom brand typeface for marketing and a system font stack for the product interface.

2020 to present: The system font approach has remained stable. Slack has made minor adjustments to spacing and weight, but the underlying font stack hasn't changed. Messages still render in whatever sans-serif your OS provides.

Mobile vs. desktop differences

Because Slack uses system fonts, the rendering differs across platforms, though the differences are subtle.

On desktop (macOS), message text appears in San Francisco at what looks like 15px. The Slack desktop app on Windows renders in Segoe UI at the same logical size. Both feel native to their respective operating systems.

On mobile, the fonts are the same (San Francisco on iPhone, Roboto on Android) but sized and spaced for smaller screens. Line height is slightly tighter, and font weight appears marginally heavier to maintain readability at smaller sizes.

The brand typeface, when it appears on mobile (splash screens, onboarding), is consistent across platforms since it's bundled with the app.

Can you change the font in Slack?

No. Slack offers no font settings, no theme-level typography options, and no way to select a different typeface for your messages. Everyone in a workspace sees messages rendered in their own system font.

Slack does support basic text formatting through Markdown-like shortcuts:

• *bold* for bold
• _italic_ for italic
• ~strikethrough~ for strikethrough
• Backticks for inline code

Beyond these, there's no native way to style text differently.

However, Unicode-styled text works perfectly in Slack messages, channel topics, and status fields. Characters from Unicode's mathematical alphanumeric block (bold, italic, script, and other styles) render correctly because they're actual Unicode code points, not formatting instructions.

The BoldlyType Slack text formatter generates these styled characters. Type your text, pick a style, and paste the result into any Slack message. Other users will see the styled text regardless of their platform or settings. For a full guide on all formatting options, see our Slack text formatting breakdown.

Why Slack chose system fonts

The decision to use system fonts for message text is deliberate. Chat applications display enormous amounts of text. Loading a custom font for every message would increase bandwidth usage, slow down rendering, and risk layout shifts as fonts load.

System fonts also feel familiar. When Slack text looks like the rest of your operating system, it reduces cognitive friction. You're reading messages, not admiring typography.

This is the opposite approach from platforms like TikTok, which use custom typefaces to reinforce brand identity in every interaction. Slack prioritizes utility over brand presence in the message stream.

FAQ

What font is used in Slack messages?

Slack messages render in your operating system's default sans-serif font. On Mac that's San Francisco, on Windows it's Segoe UI, and on Android it's Roboto.

Did Slack used to use a different font?

Yes. Before 2019, Slack used Lato throughout its interface. During the 2019 rebrand, Slack switched to system fonts for messages and a proprietary typeface for brand materials.

Can I change the font size in Slack?

You can adjust font size in Slack's desktop app through Preferences > Accessibility. This changes the overall text size but not the typeface itself.

Does Slack support bold and italic text?

Yes. Wrap text in asterisks for bold, underscores for italic, tildes for strikethrough, and backticks for code. You can also use Unicode-styled text from tools like BoldlyType's Slack formatter for additional styles.

What monospace font does Slack use for code?

Slack uses your system's default monospace font. On macOS that's Menlo, on Windows it's Consolas, and on Linux it varies by distribution.